CODEWITHSUNDEEP
pythonmysqldatabasesqlalchemypythonanywhere
user2738777
user2738777

Reputation: 510

How to completely remove database connection in sqlalchemy? Giving max_user_limit on python anywhere

I am hosting a flask application on Pythonanywhere. Where I have to make few queries from the database. While using MySQLdb I am able to close all the connection to database and don't get any error. But while using sqlalchemy some how connections to the database do not get closed.

This is my connection manager class which has a method defined to close the database connection.

class ConnectionManager:
    def __init__(self):
        self.base = declarative_base()

    def get_db_session(self):
        self.engine = create_engine(get_db_path())
        self.base.metadata.bind = self.engine
        self.session_maker = sessionmaker(bind = self.engine)
        self.session = self.session_maker()
        return self.session

    def persist_in_db(self,record):
        session = self.get_db_session()
        session.add(record)
        session.commit()
        session.close()

    def close_session(self):
        self.session.close()
        self.session_maker.close_all()
        del self.session
        del self.session_maker
        del self.engine
       #self.engine.dispose()

Before returning the response form the app I call close_session method. So my question basically is where I am conceptually getting wrong and how can I completely remove database connection.

Upvotes: 2

Views: 3052

Answers (1)

univerio
univerio

Reputation: 20548

This is caused by connection pooling. You can disable connection pooling by using NullPool.

self.engine = create_engine(get_db_path(), poolclass=NullPool)

Be careful though, this may not be a good idea in a web app if each web request needs a DB connection.

Upvotes: 4

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